1. Field
Embodiments of the present application relate to a rotor for a motor, a motor having the same and a method for manufacturing the same and, more specifically, to a rotor for a motor having a rotor tube, a motor having the same and a method for manufacturing the same.
2. Background
Motors are devices that convert electric energy to rotational energy using a force applied to a conductor in a magnetic field. Recently, as applications of the motors increase, functions of the motors become important. Particularly, with rapid electronization of automobiles, a demand for the motors applied to a steering system, a braking system and a design system, etc. is increased dramatically.
Conventionally, the motors are provided with a shaft formed to be rotatable, a rotor coupled with the shaft, and a stator fixed inside a housing, wherein the stator is installed along a circumference of the rotor with a gap. A coil forming a rotational magnetic field is wound around the stator so as to induce an electric interaction with the rotor to rotate the rotor. When the rotor is rotated, the shaft is rotated to create or assist a braking force or a steering force.
Here, the rotor may be provided with a rotor tube in a tubular form, a rotor core coupled to a circumferential surface of the rotor tube, and magnets. The shaft may be press-fitted into the rotor tube. The rotor core may be press-fitted around the circumferential surface of the rotor tube.
Meanwhile, the rotor tube may be easily deformed while the rotor core is coupled to the rotor tube, because the rotor tube is thin. When the deformation of the rotor tube occurs, inner and outer diameters of the rotor tube may be changed so that a quality of the motor may become an issue. In addition, there is a problem that chips may occur while the rotor core is press-fitted around the rotor tube.
In addition, a slip may occur between the rotor tube and the rotor core when the motor rotates at a high speed. When the slip is sustained, a problem of separation of the rotor core from the rotor tube may occur.